Perhaps Ernie is confident that after all of last season, the squad knows how to play 4 - 3 - 3 and 4 - 4 - 2 (diamond, or no diamond), so if 3 - 4 - 3 (or 3 - 5 -2) ends up not being plan A, he probably feels we can switch to plan A at any point, so why not maximise the amount of time the new formation gets to bring it up to speed?
Would be a bit strange practicing a Plan B for the entirety of pre-season if you don't think you're going to use it most games, no? Surely pre-season is to get the team comfortable and ready to go, not rever back to a different formation when the real thing starts?
Guess we'll wait and see. Be interesting to see how we line up against City.